Simply fill the pen with water and start coloring the pictures printed on each card. Magically, vibrant colors suddenly appear! Meanwhile, as kids colors, they're learning about numbers, shapes, basic words, and more. Learning becomes amazing! Set of cards that reveal brilliant colors when wet Encourages writing skills, number learning, early reading skills, shape learning Features fun cranes, dump trucks, bulldozers, and more Learn numbers, shapes, and basic words Colors disappear when cards dry - Ready to be colored in again!